1. Field of the Invention
The present invention relates to integrated circuit packages, and more specifically, to the production of a chip scale integrated circuit package using a lead frame.
2. Related Art
The use of a lead frame provides an inexpensive means for IC package manufacturing. Etching or stamping a sheet of thin metal to produce the desired lead frame patterns is a well-known manufacturing process, and is conducive to high-volume, low-cost production. In addition, the lead frame panel provides a support framework for the IC chips during IC package assembly. However, as FIGS. 1d-1 through 1d-3 show examples of common IC packages using lead frames. FIG. 1d-1 shows a small outline package (SOP) 191. FIGS. 1d-2 shows a pin-through hole (PTH) package 192. FIGS. 1d-3 shows a plastic leaded chip carrier (PLCC) 193.
As IC chip device densities increase and IC package sizes decrease, the geometries used in the electrical communication paths between the IC chip and the PCB decrease. For example, a chip scale package requires that the protective casing be no more than 20% larger than the IC chip. As a result, the area available for the electrical paths provided by the lead frame is significantly reduced, demanding much finer lead frame patterns. Accordingly, it is desirable to provide an IC packaging method that allows the use of a lead frame in a chip scale package.